Suction conveying means for a hammer mill



J. G. BRYANT 2,800,28

sucTIoN CONVEYING MEANs EOE A HAMMER MILL July 23, 1957 Filed Jan.

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A ttor/7gg United States Patent O 2,800,286 SUCTION CONVEYING MEANS FORA HAMMER MILL James G. Bryant, Port Huron, Mich. Application January 20,1954, Serial No. 405,065 1 Claim. (Cl. 241-57) This invention relates toa hammer mill and more particularly to such a mill wherein the mill isconstructed with a suction fan at the discharge end thereof to moreeffectively draw air and ground material through the screen of the mill.

The cardinal object of the invention is the provision of a suction fanat the discharge end of the hammer mill for creating a suction beneaththe screen of the mill for assisting passage of ground material into thefan housing.

It is also an important object of the invention to provide a hammer millwherein the suction fan is positioned at one end of the mill and whichis rotatable at right angles to the rotation of the hammer mill grindingunit to thereby create a direct suction of air through the mill.

More specilically, it is an object of the invention to provide a hammermill wherein an air inlet is so positioned with respect to the grindingcompartment and a suction fan located at one end of the mill to create adirect pull upon the air entering the grinding compartment for effectingpassage of ground material into the suction fan compartment, as well asto provide an inclined trough beneath the grinding compartment, thelatter defining an air inlet for the passage of air beneath the screenof the grinding compartment.

Additional objects, advantages and features of invention will beapparent from the following description, considered in conjunction withthe accompanying drawing, wherein,

Figure 1 is la longitudinal sectional view through a hammer millembodying the invention,

Figure 2 is a perspective view of the trough employed beneath thegrinding chamber of the mill.

Referring to Figure 1 of the drawing, a hammer mill l is show-n ofconventional construction insofar as the crusher 11, grinding chamber 12and screen 13 is concerned, these devices functioning as heretofore andis well understood in the art.

The front wall 14 of the mill housing 15 terminates a distance below thehorizontal axis of the hammer mill shaft 16, forming a-n opening 17 andaround this opening a plate 18 is suitably welded as well as to the basebeam 19 of the mill frame. The plate 18 has a circular opening 20 indirect line with the lower portion of the screen 13.

A fan housing 21 includes a rear wall 22 having a circular opening 23 inregistry with the opening 20 of the plate 18, the rear wall 22 beingsuitably secured to the plate 18 by means of bolts and nuts 24, accessto which may be had through openings 25 formed at suitable points in theside Walls of the mill, these openings being closed by suitable closureplates 26. The openings 20 and 23 form the discharge into the fancompartment.

The lower portion of the fan housing 21 is mounted upon a base 27consisting of channel irons which extend transversely and longitudinallyof the housing, the longitudinal channel irons 28 also forming thesupport for a motor pedestal 29.

The front wall 30 of the fan housing has an opening 31 formed therein ofa diameter greater than the diameter of the fan 32 to be employedtherein to permit 2,800,286; Patented July 23, 1957 installation withinthe housing, the opening being closed by a plate 33' which may besuitably bolted as at 34 to the wall 30.

Anl electric motor 35 is mounted upon the pedestal 29 in any suitablemanner, and in order that the motor shaft 36 may pass into the fanhousing 21, the plate 33 is formed with a medial opening 37.

From the construction thus far described it will be noted that bypositioning the fan housing at the front end of the mill housing, thefan 32 will be rotated at right angles to the rotation of the hammermill unit in the grinding chamber 12 effecting a directdraft of airthrough the air inlet 38 into the material being ground and through thescreen 13 from whence the material passes into the fan housing 21.

A trough 39 is employed for conveying ground material to the fan housing21, the trough being of semicylindrical form at the juncture with theopening 20. The trough includes a bottom wall 40 converging upwardlywith respect to the upper edges 41 of the trough and terminates in adownwardly extended lip 42 to provide rigidity. Preferably the trough 39is welded to the plate 18 and along the upper edges 41 to the side wallsof the mill as indicated at41.

Aligned with the trough 39 there is a trough extension plate 43, whichis detachably mounted beneath the bottom plate 44 and intake plate 45 ofthe mill forming an air intake 46.

Thus, it will be seen that a trough is provided under the grindingchamber and the screen, arranged at a slight inclination in thedirection of the bottom plate and intake plate to form the air intake,producing a flow of air under the screen, through the trough and intothe fan housing. The air intake 46 as here defined makes it unnecessaryfor the trough to be at a steep inclination,

thereby reducing the over-all height of the mill, and this pitch of thetrough makes it unnecessary to employ high air velocity which would berequired in a trough horizontally disposed, thereby resulting in asaving in fan horsepower.

While I have shown and described a preferred form of the mill, this isby way of illustration only, and I consider as my own all suchmodifications in construction as fairly fa-ll Within the scope of theappended claim.

I claim:

A suction conveying means for a hammer mill comprising a housing havinga material crusher at one end thereof and a suction housing and fan atthe other end thereof, a grinding chamber between said material crusherand said suction housing, said grinding chamber being spaced from thematerial crusher forming an air inlet passage opening upon said grindingchamber, said grinding chamber having a bottom plate, an inclined troughbeneath said grinding chamber, the lower end of the trough being incommunication with the intake opening of the suction housing, the upperend of said trough terminating beneath the bottom plate of the grindingchatnber and a detachable extension for said trough being positionedbeneath and extending beyond the bottom plate thereby defining` an airinlet passage outwardly of the hammer mill housing.

References Cited in the tile of this patent UNITED STATES PATENTS SandorJuly 28, 1953

